The Michigan Department of Natural Resources says over 2,000 pounds of of live, illegal red swamp crayfish were recently seized by conservation officers. It's the largest aquatic invasive species seizure by the Michigan DNR in history. Officers in St. Clair County were notified by U.S. Customs and the U.S. Fish and Wildlife Service when a commercial hauler transporting the invasive species was denied entry into Sarnia, Canada from Michigan.

Assisted by customs officials, DNR officers stopped the truck and obtained 55 bags of live crayfish. After interviewing the driver, they learned the truck originated from Canada and made stops in Maryland and Arkansas to pick up cargo prior to attempting its return to Canada.

Red swamp crayfish burrow and create shoreline erosion, creating instability. Additionally, they compete with native crayfish, reducing the amount of food and habitat available for amphibians, invertebrates and juvenile fish.

Red Swamp Crayfish (Courtesy: Michigan DNR)

The first concern regarding red swamp crayfish in Michigan was in 2013, when conservation officers learned the illegal crayfish was being used as bait in southwest Michigan. The first live infestations in Michigan were detected and reported in 2017.

Native in southeast states of the U.S., red swamp crayfish are the most widespread invasive crayfish in the world. Any possession of live red swamp crayfish in Michigan is illegal. The DNR is working to increase awareness and reporting of the illegal crayfish, in addition to removing infestations from confirmed locations.